--- title: Containerize a Node.js application keywords: node.js, node, containerize, initialize description: Learn how to containerize a Node.js application. aliases: - /get-started/nodejs/build-images/ - /language/nodejs/build-images/ - /language/nodejs/run-containers/ --- ## Prerequisites * You have installed the latest version of [Docker Desktop](../../get-docker.md). * You have a [git client](https://git-scm.com/downloads). The examples in this section use a command-line based git client, but you can use any client. ## Overview This section walks you through containerizing and running a Node.js application. ## Get the sample application Clone the sample application to use with this guide. Open a terminal, change directory to a directory that you want to work in, and run the following command to clone the repository: ```console $ git clone https://github.com/docker/docker-nodejs-sample ``` ## Initialize Docker assets Now that you have an application, you can use `docker init` to create the necessary Docker assets to containerize your application. Inside the `docker-nodejs-sample` directory, run the `docker init` command in a terminal. `docker init` provides some default configuration, but you'll need to answer a few questions about your application. Refer to the following example to answer the prompts from `docker init` and use the same answers for your prompts. ```console $ docker init Welcome to the Docker Init CLI! This utility will walk you through creating the following files with sensible defaults for your project: - .dockerignore - Dockerfile - compose.yaml - README.Docker.md Let's get started! ? What application platform does your project use? Node ? What version of Node do you want to use? 18.0.0 ? Which package manager do you want to use? npm ? What command do you want to use to start the app: node src/index.js ? What port does your server listen on? 3000 ``` You should now have the following contents in your `docker-nodejs-sample` directory. ```text ├── docker-nodejs-sample/ │ ├── spec/ │ ├── src/ │ ├── .dockerignore │ ├── .gitignore │ ├── compose.yaml │ ├── Dockerfile │ ├── package-lock.json │ ├── package.json │ ├── README.Docker.md │ └── README.md ``` To learn more about the files that `docker init` added, see the following: - [Dockerfile](../../engine/reference/builder.md) - [.dockerignore](../../engine/reference/builder.md#dockerignore-file) - [compose.yaml](../../compose/compose-file/_index.md) ## Run the application Inside the `docker-nodejs-sample` directory, run the following command in a terminal. ```console $ docker compose up --build ``` Open a browser and view the application at [http://localhost:3000](http://localhost:3000). You should see a simple todo application. In the terminal, press `ctrl`+`c` to stop the application. ### Run the application in the background You can run the application detached from the terminal by adding the `-d` option. Inside the `docker-nodejs-sample` directory, run the following command in a terminal. ```console $ docker compose up --build -d ``` Open a browser and view the application at [http://localhost:3000](http://localhost:3000). You should see a simple todo application. In the terminal, run the following command to stop the application. ```console $ docker compose down ``` For more information about Compose commands, see the [Compose CLI reference](../../compose/reference/_index.md). ## Summary In this section, you learned how you can containerize and run your Node.js application using Docker. Related information: - [Dockerfile reference](../../engine/reference/builder.md) - [Build with Docker guide](../../build/guide/index.md) - [.dockerignore file reference](../../engine/reference/builder.md#dockerignore-file) - [Docker Compose overview](../../compose/_index.md) ## Next steps In the next section, you'll learn how you can develop your application using containers. {{< button text="Develop your application" url="develop.md" >}}